Generally, an airtight container includes a container body and a lid for opening or closing an opening of the container body. A container having a packing member for airtight sealing, which is installed on one of a container body and a lid thereof, may be called an airtight container. Further, a container even without a packing member may be called an airtight container or a food container. Further, such an airtight container or food container may be used as a small article container for storing various small articles according to user intent.
In a conventional airtight container as described above, a lid opens or closes an opening of a container body. A rotating knob having a latching groove is formed on one of the container body and the lid, and a protrusion to be inserted into the latching groove to maintain a locked state is formed on the other thereof. When the latching groove and the protrusion are coupled to each other, the lid covers an opening of the container body to maintain the locked state. When the latching groove and the protrusion are decoupled, the locked state is released.
Meanwhile, in order to open a lid of a conventional container from an opening of a container body, either hands of a user may be used to simultaneously hold proper circumferential portions of the lid and then lift up the lid or one hand may be used to hold the container body while the other hand is used to hold a knob protruding from one side of the lid and then lift up the lid. The container may have various size and shapes.
A conventional airtight container may include a protruding knob formed on one selected from four corners of a lid, or flat plate-shaped knobs usable to lift the lid and formed on opposite side walls of the lid. Therefore, when the lid is to be opened from the container body, if a user holds a container body with one hand and lifts up a knob formed one side of the lid with the other hand, the container body may be shaken by an opening force due to a tight locked state, and thus food and broth may spill out from the container body.
Particularly, the larger the size of a conventional airtight container is, the more frequently the contents contained in the container body may escape due to shaking due to an opening force of the lid. This is because a large airtight container inevitably requires a large lid, and the large size of the lid inevitably results in a large rotating knob having a latching groove for maintaining the lid in a locked state with the container body or a large latching protrusion inserted into the latching groove, thereby increasing the latching load for maintaining the tight locked state. Therefore, a predetermined force is required to open the lid, and thus housewives and children who relatively frequently use an airtight container cannot easily open the lid without shaking of the container body.
Meanwhile, in the conventional airtight container, when the container body and the lid are not maintained in a locked state, the rotating knob formed on opposite side walls of one selected from the container body and the lid is maintained in a state where the knob elastically protrudes in a horizontal direction from the opposite side walls of the container body. For example, in a case where a plurality of airtight containers each including a lid and a container body separated from each other are stacked and packed, when only a plurality of container bodies are stacked and then a plurality of stacked lids are stacked on the stacked container bodies, rotating knobs formed on opposite side walls of the container bodies are maintained in a state where the knobs protrude toward one side without being folded by themselves due to an elastic force.
When the rotating knob is maintained in the state where the knob protrudes toward one side as described above, a packaging case for packing the airtight containers is required to have a relatively large size and thus have an unnecessarily increased capacity. Moreover, it is difficult to maintain an alignment state of stacked units in the package or a shape of the package.
In brief, the rotating knob having a latching groove and installed on either of the container body and the lid configuring the conventional airtight container as described above just maintains or releases a locked state of the container body and the lid, but does not have a configuration which enables the rotating knob to directly push the lid up from the container body to open the lid.
Prior Art document 1: Korean Patent Publication (Application No. 10-2003-0074940; published on Apr. 29, 2005), Prior Art document 2: Korean Utility Model Registration Publication (Application No. 20-2003-0008580; published on Jun. 18, 2003), Prior Art document 3: Korean Utility Model Registration Publication (Application No. 20-2003-0039462; published on Mar. 24, 2004), and Prior Art document 4: Korean Utility Model Registration Publication (Application No. 20-2004-0015848; published on Sep. 1, 2004).
Meanwhile, FIG. 5 is a partial cross-sectional view showing an airtight structure between a container body and a lid, which configure a conventional A-type airtight container and include a locking member.
As noted from the drawing, a conventional airtight container includes a container body 100 and a lid 101 for opening or closing an opening of the container body. The lid 101 has a groove 104 formed inside a peripheral edge portion 103 thereof, and a packing 105 for maintaining airtightness of the container body is disposed in the groove and comes into contact with a bump 106 formed in a circumferential direction of the container body 100 to maintain the airtightness. Further, the lid 101 has a latching piece 108 disposed thereon, which protrudes from an inner wall of a locking member 107. The latching piece 108 can be tightly engaged with or released from a latching bump 109 protruding from the outer wall of the container body 100 to maintain or release the air-tight coupling between the container body 100 and the lid 101.
However, in the conventional airtight container as described above, when the lid is locked in a part of four sides of the airtight container by the locking member, a portion of the lid of the remaining portion except for a corresponding portion of the lid that maintains a locked state is lifted upwards. Therefore, air frequently flows into and out of the container body, and the fluid of food contained in the container body spills out to the outside. In addition, with respect to the lid, since the packing is forcedly inserted into the lid, mold is generated in the packing when used for a long period of time, and the packing is decayed or deformed so that a spaced gap is generated in the long run. As a result, air frequently flows into and out of the container body and the fluid of food contained in the container body spills out to the outside.
Meanwhile, FIG. 6 is a partial cross-sectional view showing an airtight structure between a container body and a lid, which configure a conventional B-type airtight container and include a locking member.
As noted from the drawing, a conventional airtight container includes a container body 200 and a lid 201 for opening or closing an opening of the container body 200. The lid 201 has a groove 203 formed inside a peripheral edge portion 202 thereof, and a ∩-shaped packing 208 for maintaining airtightness of the container body 200 is disposed in the groove and comes into contact with a bump 204 formed in a circumferential direction of the container body 200 to maintain the airtightness. Further, a protrusion 207 protruding from the outer wall of the container body 200 is inserted into and tightly engaged with or released from a hole 206 formed in a locking member 205 disposed on the lid 201 to maintain the coupling between the container body 200 and the lid 201.
However, with respect to the lid, since the ∩-shaped packing is forcedly inserted into the lid or installed in a double injection manner (insert injection) and a gap of the packing is very narrow such that the bump of the container body can be airtightly received, the lid is not easily opened because the bump of the container body is held by a strong elastic force of the packing in a state in which the bump of the container body is airtightly inserted into the packing while the lid is opened. In addition, even when the lid is opened, the container body is shaken by an opening force applied to the lid, and thus the fluid of food contained in the container body spills out to the outside.
Meanwhile, FIG. 7 is a partial cross-sectional view showing an airtight structure between a container body and a lid, which configure a conventional C-type airtight container and include no locking member.
As noted from the drawing, a conventional airtight container includes a container body 300 and a lid 301 for opening or closing an opening of the container body 300. The lid 301 has an inner wall 303 having a predetermined height and formed inside a peripheral edge portion 302 thereof, and a holding wall 305 having transverse elasticity is disposed on one side with a spaced gap 304 between the inner wall 303 the one side so that a bump 306 portion formed in a circumferential direction of the container body 300 is inserted into the spaced gap 304 and supported by the holding wall 305. Thus, the holding wall maintains a fixed state between the container body 300 and the lid 301.
However, in the airtight container as described above, the bump 306 of the container body is inserted into the spaced gap between the inner wall and the holding wall of the lid without a locking member so that the container body and the lid are just maintained in a fixed state. Therefore, air frequently flows into and out of the container body, and the fluid contained in the container body spills out to the outside.
Further, FIG. 8 is a partial cross-sectional view showing an airtight structure between a container body and a lid, which configure a conventional D-type airtight container and include no locking member.
As noted from the drawing, in a conventional airtight container, a latching bump 403 facing one side is formed on an inner wall 402 of an edge portion 405 formed along a circumferential direction of an upper side of a container body 400, and an insertion groove 406 into which the edge portion 405 of the container body 400 is to be inserted is formed inside a peripheral edge portion 410 of the lid 401. Further, a protrusion 408 facing the latching bump 403 is formed on an inner wall 407 of the lid 401 configuring the insertion groove 406. When the lid 401 is closed, the protrusion 408 comes in contact with a portion just below the latching bump 403, so as to prevent the lid 401 from being easily separated from the container body 400.
However, the latching bump and the protrusion prevents the lid from being easily separated from the container body but cannot maintain the airtight state through contact between the latching bump and the inner wall of the protrusion. The main reason why the airtight state cannot be maintained is that, since the container body is made of polypropylene (PP), and the lid and the protrusion formed on the inner wall of the lid are made of polypropylene (PP), the latching bump and the protrusion are worn down when the lid opens or closes the container body repeatedly for a long period of time, so that the airtight state cannot be maintained. Further, since the lid and the latching bump are made of thin polypropylene (PP), the lid and the latching bump act sensitively to a change in temperature and thus have deformed shapes, so that it is difficult to maintain the airtight state. Therefore, air frequently flows into and out of the container body of the airtight container, and the fluid of food contained in the container body spills out to the outside.
In addition, FIG. 9 is a partial cross-sectional view showing an airtight structure between a container body and a lid, which configure a conventional E-type airtight container and include no locking member.
As noted from the drawing, a conventional airtight container includes a container body 500 and a lid 510 for opening or closing an opening of the container body. The drawing illustrates an airtight container having no locking member installed on one of the container body 500 and the lid 510 to fix the lid 510 to the container body 500.
In a conventional airtight container shown in the drawing, a packing member 511 made of soft resin or silicon is formed on an inner wall 512 of the lid 510 for opening or closing the opening of the container body 500 by double injection (insert injection) of the packing member together with the lid made of polypropylene (PP). The packing member 511 horizontally and lengthily protrudes toward one side before the opening of the container body 500 is closed by the lid 510. When the lid 510 is closed, the packing member 511 comes into contact with a wall 513 configuring the container body 500 and is bent inward and folded. Therefore, the packing member 511 comes into contact with the wall 513 of the container body so that airtightness is maintained.
However, since the packing member installed on the lid has a large working space for being in contact with the wall of the container body, the capacity of the container is reduced. In addition, when the lid is closed, the air inside the container body flows out as much as the lid is lowered to the inside of the container body, so that the inside of the container body is in a weak vacuum state. Thus, when the lid is opened again, the lid is not opened easily and the container body is greatly shaken by an opening force applied to the lid, so that food contained in the container body is spilled. Therefore, it is troublesome to install a valve for air inlet and outlet in the lid to prevent the problem described above.
Particularly, in the conventional airtight container as described above, the packing member disposed in a circumferential direction of the lid protrudes longer than necessary. Therefore, when the fluid in the container body is shaken, the contact portion between an end surface of the packing member and the wall is lifted by pressure of a fluid in the container body, and thus a gap is generated. As a result, the fluid spills out through the gap and thus airtightness cannot be maintained.
There are also various types of conventional airtight containers having a packing. However, irrespective of the presence of a locking member for binding a container body and a lid, structural defects of packings installed in all of the containers and the deformation due to the defects frequently cause air to flow into or out of the container body and causes the fluid of food contained in the container body to spill out to the outside.
Prior Art document 5: Korean Utility Model Registration publication No. 0248959 (published on Oct. 19, 2001), Prior Art document 6: Korean Patent Registered Utility Model Registration publication No. 0301897 (published on Jan. 29, 2003).